<html><body><div style="font-family: arial, helvetica, sans-serif; font-size: 12pt; color: #000000"><div>Hi everyone,</div><div><br></div><div>I've been runing 2D cylindrical FLASH simulations based on the LaserSlab setup.</div><div>I would like to study the evolution of hydrodynamic instabilities at the ablation front.</div><div><br></div><div>I attached bellow an illustration of the density map results. I only run the right side. The left part is built by the symmetry with the white axis at x=0.</div><div>In white color, I circled what is my concern. This bubbly structure seems to show that the boundary symmetry at the left edge of the numerical box isn't what I expected to be a flat laser irradiation.<br></div><div>It seems that at x=0, the laser deposition is lower. At late times, this impacts the instability growth on the axis.<br data-mce-bogus="1"></div><div><br data-mce-bogus="1"></div><div>I used the "reflect" or "axisymmetric" hydro boundary on the axis. <br data-mce-bogus="1"></div><div>I also attached some parameters from the flash.par which could be relevant to fix my issue.<br data-mce-bogus="1"></div><div><br data-mce-bogus="1"></div><div>I guess this is kind of a typical problem when you deal with such geometry.<br data-mce-bogus="1"></div><div>If you have any idea, I'll be glad to discuss about all of this.<br data-mce-bogus="1"></div><div><br data-mce-bogus="1"></div><div>Thank you!<br data-mce-bogus="1"></div><div><br></div><div><img src="cid:a38ad2cde61fc87bb0baf681365ea9d3b494081f@zimbra" data-mce-src="cid:a38ad2cde61fc87bb0baf681365ea9d3b494081f@zimbra" width="491" height="323"></div><div><br># RADIATION/OPACITY BOUNDARIES<br><br>rt_mgdXlBoundaryType = "reflecting"<br>rt_mgdXrBoundaryType = "vacuum"<br>rt_mgdYlBoundaryType = "vacuum"<br>rt_mgdYrBoundaryType = "vacuum"<br>rt_mgdZlBoundaryType = "reflecting"<br>rt_mgdZrBoundaryType = "reflecting"</div><div><br></div><div><!--StartFragment-->#CONDUCTION <!--StartFragment-->BOUNDARIES<!--EndFragment--> <br><br>diff_eleXlBoundaryType = "neumann"<br>diff_eleXrBoundaryType = "neumann"<br>diff_eleYlBoundaryType = "neumann"<br>diff_eleYrBoundaryType = "neumann"<br>diff_eleZlBoundaryType = "neumann"<br>diff_eleZrBoundaryType = "neumann"<br><br>#HYDRO <!--StartFragment-->BOUNDARIES<!--EndFragment--><br><br># Hydro boundary conditions:<br>xl_boundary_type = "reflect"<br>xr_boundary_type = "outflow"<br>yl_boundary_type = "outflow"<br>yr_boundary_type = "outflow"<br>zl_boundary_type = "reflect"<br>zr_boundary_type = "reflect"<br><!--EndFragment--> <br># LASER PARAMETERS <br><br>ed_laser3Din2D = .true.<br>ed_laser3Din2DwedgeAngle = 0.1<br><br>ed_lensX_1 = 1000.0e-04<br>ed_lensY_1 = 0.0e-04<br>ed_lensZ_1 = -1000.0e-04<br>ed_lensSemiAxisMajor_1 = 1000.0e-04<br>ed_lensSemiAxisMinor_1 = 1000.0e-04<br>ed_targetX_1 = 0.0e-04<br>ed_targetY_1 = 0.0e-04<br>ed_targetZ_1 = 1400.0e-04<br>ed_targetSemiAxisMajor_1 = 1000.0e-04<br>ed_targetSemiAxisMinor_1 = 1000.0e-04<br>ed_pulseNumber_1 = 1<br>ed_wavelength_1 = 0.351<br>ed_crossSectionFunctionType_1 = "gaussian2D"<br>ed_gaussianExponent_1 = 4.0<br>ed_gaussianRadiusMajor_1 = 900e-04<br>ed_gaussianRadiusMinor_1 = 900e-04<br>ed_numberOfRays_1 = 16384<br>ed_gridType_1 = "radial2D"<br>ed_gridnRadialTics_1 = 512<br>ed_semiAxisMajorTorsionAngle_1 = 0.0<br>ed_semiAxisMajorTorsionAxis_1 = "x"<br><br><br><br><br></div><div><br></div><div data-marker="__SIG_POST__">--</div><div><div style="text-align: left;" data-mce-style="text-align: left;"><span style="color: #000000;" data-mce-style="color: #000000;">Thibault Goudal</span></div><div style="text-align: left;" data-mce-style="text-align: left;"><span style="color: #000000;" data-mce-style="color: #000000;">PhD Student CEA</span></div><div style="text-align: left;" data-mce-style="text-align: left;"><span style="color: #000000;" data-mce-style="color: #000000;">CELIA CNRS UMR5107 laboratory</span></div><div style="text-align: left;" data-mce-style="text-align: left;"><span style="color: #000000;" data-mce-style="color: #000000;">+33664160842</span></div><div style="text-align: left;" data-mce-style="text-align: left;"><span style="color: #000000;" data-mce-style="color: #000000;">thibault.goudal@u-bordeaux.fr<br></span></div></div><div></div></div></body></html>